Friday, June 22, 2018

More Videos, Hopefully Better Video

I purchased a new computer this year with the main goal to create better videos, besides that my old computer was several years old and really slow. The new computer is tiny in size but powerful and runs really cool. After several years of publishing this blog I am amazed at how many views there have been over time, very close to 300,000 now.  If video is done well, I think it is more interesting than written articles. In that I am doing most of this by myself, it is rather hard to get images and video of model airplanes while flying at the same time.

The first videos will probably be more still images because that is what I have to tell the story. Besides model airplanes I hope to get back to more science and other videos. Mainly I just hope to keep learning, improve, and have fun. I have been thinking a lot about what makes an interesting story for the intended audience.  My most recent narrated video is a story about how I decided to build a free flight PeeWee 30 model and what I needed to learn. I have much to learn about narration and editing but will keep working on it.

Witch Hawk 500

I am really close to finishing up a couple of free flight models for the 2018 contest season. The Witch Hawk 500 is my first larger glow powered free flight using a K&B .19 engine for power. This is the first time running an engine on bladder pressure so I have been running it on a test stand. 

Almost completed is an E36 NOS free flight model, design by Don DeLoach of a classic glow model the Eureka. My skill level is still where I do not feel comfortable with really fast climbing airplanes, this should be more my speed.

Eureka E36 NOS

I have made one short flight with the 1/2 A Streak model built this winter, broke the fragile plastic prop and it started to rain so did not get anymore flights in.

1/2 A Streak

In the works are a couple of videos, one about free flight history and the older design models I have built because of my interest in model aviation history. Another video is about my model aviation history, and most of the different aspects of the hobby that I have enjoyed.

Bill Kuhl

Thursday, June 14, 2018

Fishing Distraction to Model Airplane Hobby

To me it seems like events that a person really looks forward to seem like forever in the future and then all of a sudden come very quickly.  In July I plan to compete again at the 2018 Free Flight Nats in Muncie Indiana. There are two models I am still finishing up construction on and another one that has not been test flown yet.  When the weather is nice I would rather go fishing or fly model airplanes. With the opening of Largemouth Bass season it seems like there is a week that the fish are pretty easy to catch, even the big ones. That time period has passed but I still like to try during the hour before sunset. RC sailplane flying I sneak in time flying my UMX Radian at a local park during lunch or right after work.

Evening Fishing
Installed New Motor in UMX Radian

For the first time I will have articles in the 2018 NFFS Symposium report coming out this summer. One article is about Viscous DT timers and the other is about recruiting youngsters to free flight model aviation.  I created a website article that is more of a tutorial about the theory on the science of how a viscous DT timer operates; the Symposium article is more about suggestions on more effectively using a viscous DT timer in a free flight model. For testing purposes I installed a viscous DT timer in a rather small sport model the Blue Ridge Special available in a 2 pack semi kit from Volare, construction of the second model is well along. It really did not add much weight to a 14” rubber model and it brings it down effectively by popping up the front of the wing. I have a short video on this and working on more videos somewhat like the blog reports.

Blue Ridge Special

For the first time I have almost completed a larger glow powered free flight, Witch Hawk 500 powered by a K&B .19.  This is my first time running a glow motor on bladder pressure so I have done a lot of test stand running. To start a larger glow engine on a free flight model I also mounted an electric starter on a stool with a foot pedal switch. The plane needs to be balanced, sprayed with clear dope, and DT system installed.

Witch Hawk 500

Starter with Foot Pedal Switch

For this season I had put additional clear dope on my Basic Yeller PeeWee 30 model and replaced some parts in the PeeWee .020 engine.  It has made several flights this year which looked really good. I have ready to fly now a ½ A Streak powered by a K&B .049. The motor has been run several times and the plane test glided, looking forward to first powered test flights.

Basic Yeller Flies Again

1/2 A Streak

That is what I have been doing.

Bill Kuhl

Related Links  Viscous DT Tutorial  DT System Added to Blue Ridge Special  Blue Ridge Special DT Flying Clip  Blue Ridge Special 2-pack Short Kits

Monday, May 14, 2018

Flying Aces Moth

To start out my winter 2017/2018 model building I picked out a classic rubber power model that had been occupying shelf space in my basement for a while, the Flying Aces Moth. This was from a Peck full-kit, I also have a Volare semi-kit in waiting to possibly build an improved version from what I learn from this one.  George Bredehoft tells me “the Moth originally appeared in the August 1937 Flying Aces magazine - and then was REPRINTED in the August 1941 Flying Aces magazine, by popular demand.” I understand there was a modified plan in Aeromodeller with a shorter nose for plastic propellers. For my model I purchased a balsa propeller blank from Volare, I was amazed the balsa propeller weighs almost half the weight of the included plastic propeller.

Construction is really typical of a stick and tissue model, the 3/32” square fuselage pieces were easier for me to handle than 1/16” square often used. I used a viscous DT timer built from a rotary damper I had purchased for under $3. For the first time I tried a wire in a tube bearing point for the front of the stab instead of just using rubber bands, it needed to be reinforced but might work out well. The model was covered in Esaki tissue and sprayed with nitrate 50/50 dope, the first model sprayed with my new airbrush system. Also the first time for using a wire to the front of the shaft freewheel system.  For rubber I used 12 grams of 3/32” rubber braided.

When I finished the model I was anxious to fly it although there was snow on the ground, I took it along with me for a cross country skiing outing and did some short flights over the now. It sure wanted to fly, too much to the left and up. I assumed like many rubber models it would need some down and right thrust which I added. The next flights were better but it still needed more right, I put that into the rudder. If the turn was gentle if flew nice but if too severe a turn it would hit the ground which was not snow covered any longer. The long landing gear broke loose from the bottom of the fuselage easily. I fixed it many times. After so many times I just rubber banded the gear to a cross piece in the fuselage, this saved the plane from further breakage.  The nose area was taking a beating too and I did some reinforcing there, the balsa tends to compress and then the thrust settings change. I now have some thin plywood in the contact areas around the propeller hub. 

Further flights were really inconsistent, sometimes the plane would not have enough right turn and other times too much and it would do a slow spiral into the ground. I would patch up the plane and just keep trying again. For the landing gear issue I ended up just adding another cross member of hard balsa and then gluing the wire to it with UHU POR glue. This glue has some elasticity and the landing has stayed intact through many flights. 

Major Rebuild

The turning point came when the fuselage broke in several places after a crash. I was tempted to destroy the plane and save myself further aggravation. After thinking to myself I was not going to give up, I ripped most of the covering from the fuselage and made repairs. Much of the vertical fin was redone and a small rudder tab was created. The amount of right thrust was decreased too; I feel that might be part of the issue too. As had been recommended I moved the rear peg up further because the rubber in the narrow rear part of the fuselage was ripping the tissue. This moved the CG forward a slight amount requiring more incidence but the recovery from a stall was much better.

More flights with hand winds showed great promise, no crashes under power. Flying on several days the trim appeared to stay pretty much unchanged. Recently I had a larger site to fly from and I made several flights using the winder gradually getting up to 400 turns. The plane handled greater torque fine, the glide might need a little tweaking yet. I really feel a sense of accomplishment and that I have learned much from working with this airplane. In the future I plan to build another one from the Volare short-kit and try to use the knowledge from the first one to build a better version from the start.

Bill Kuhl

Check Out my New Viscous DT Tutorial for Students

Wednesday, May 9, 2018

Model Aviation Youth Success Story

Saturday May 5, 2018 was a great day at the Victor Valley R/C Flyers flying field located in Hesperia California for the Youth Foam Plate Rubber Powered Plane and Hand Chuck Glider event.  Over 50 entries total and 19 in the new AMA Alpha class. Winners were awarded plaques and merchandise. Many families attended as can be seen in the images. 

These award winners are the students with best scores. But all of the students gain a great deal of knowledge each year. Jokingly I was told that my classes had enrollment of over sixty per class for next year. I was not laughing. I may need to franchise to fulfill the demand. Ronnie Espolt

This blog post will be short and quote from comments on the Facebook group that Ronnie Espolt started the Youth and Education, Model Aviation Group. Ronnie works harder than anyone I know of in teaching model aviation to kids through classes at schools and to different groups. Quoting in a recent email from Ronnie gives an idea just how busy he is: “I have just a few things to work on now. County Fair in two weeks, buddy box this Saturday another for Millionaire Minds Kids Club in June. National Night Out, National Model Aviation Day, Youth day at Planes of Fame Museum.” Ronnie Espolt

Ronnie and I communicate almost daily and we have both been working with the ideas in building rubber powered model planes primarily out of foam plates but using a balsa stick for the fuselage. This past year the Academy of Model Aeronautics made available a really slick looking plane of this type with a rubber winder included for a great price known as the “Alpha”. One of the Alpha models had a 3 minute flight at the contest. Rick Pearson a member of the Victor Valley RC Flyers took many of the pictures.

Quotes from Youth and Education, Model Aviation Group

“I tried an idea that worked well. My traditional contest has been an 18" Hand Chuck and a Foam Plate Rubber Powered Plane. All the students from the school come with families a long with my youth club. So each year we have had kids at the field with no planes to enter. These kids have always felt left out. This year I added the AMA Alpha Class and sold the kits with winder. We sold 19 for the contest at the event. The remaining Alpha planes were used as prizes for contestants. This kicked our entry count to over fifty. I have 38 new youth AMA memberships to send into headquarters.” Ronnie

Jim N. “Ronnie, what a fantastic thing you do all just because you can and you have a tremendous heart for the future. These kids would most likely not been exposed to model airplanes let alone all the little things that come along with it; science, math, and history. YES, history. Talking to kids about the different roles different planes filled both in peace and at war.  There are so many kids out there with no solid role model. Ronnie you deserve a huge thank you from everyone who cares about our youth. The best part is; Ronnie knows nothing of this. He's just a great guy and thought, hey, cool. I have kids that like to play with the same things as I do.”

Related Links   Victor Valley Facebook Page  "Youth and Education, Model Aviation Group" Purchase the AMA Alpha  AMA Alpha & Postal Contest Join Academy of Model Aeronautics  National Free Flight Society   - I recommend highly Simple Foam Free Flight Airplane  Detailed instructions on building rubber powered foam plate model airplane on my website. About Millionaire Mind Kids (MMK)

Wednesday, May 2, 2018

Details Matter in Model Aviation

Becoming successful in model aviation requires that one be detailed oriented, a very good skill to have but not always a trait that comes naturally to many people. This statement in an article in Inc. Magazine I found applies well, “Details often make or break accomplishments.”  Although I feel if one tries to become too perfect all at once it can be overwhelming and frustration will follow. For example I am learning the hard way when model plans specify a certain weight of wood and type of grain of wood, there really is a reason the designer specified that. In the past I might have used whatever I found at the hobby shop. Often the plane ended up too heavy to fly well but more recently I have used wood that was too light for the particular spot on the airplane.  

Bad Axe Embryo has Fuse DT 

An example of this was on the fuselage of a contest winning embryo design the Bad Axe from Volare. This was a short-kit which provided the more difficult to cut out sheet pieces but the builder provided the balsa strip pieces in the kit. It is normal practice to use hard balsa longerons for the square pieces that run the length of the edges of the fuselage and lighter wood for the cross members. With too light of wood for the longerons I was breaking the pieces just trying to construct the fuselage, if I added reinforcement in a spot it would just break next to where the reinforcement ends. Trying to cover the model with tissue and not get sagging areas is impossible too. When you try to fly the model it is so difficult to hold the model without breaking a fragile longeron even with a fairly gentle grip. 

Lighter Guillow's Super Cub Flies Well

Building a model that is too heavy is not good either and easily done. Several years ago I built a Champ kit that just had too heavy of balsa in the kit. No doubt this can happen even in what would appear to be a quality kit. It was easy to cover the model with tissue as the structure was rigid and it did not seem terrible heavy lifting it as it was a small model. Trying to fly the model it was difficult to adjust and it always appeared to me to be flying at the edge of a stall, I added more rubber which helped but now it was flying faster and crashing harder. Each repair added a little more weight and after major damage I gave up. I had trouble with a Guillow’s Cessna 180 also so when I built the smaller Super Cub kit which has the same basic structure I built it lighter by building a lighter tail with balsa curved around a form. The plane did not need any nose weight and it flies well.

Champ was too Heavy

In a more current project I believe my airplane came out too heavy for the wing area and the amount of rubber the model was carrying. I wanted to try a new to me electronic DT system that added 9 grams which does not seem too heavy but when you are on the edge it might be. Test glide without the rubber motor and tiny amount of clay for balance looked good.  Reduced winds test flights were a constant battle with a stall after the rubber ran out. I added right side thrust, down thrust and right rudder tab. To me the 16 strands of rubber seemed like a heavy load. Before destroying the fuselage the last time I had glided the model from a small hill, the glide looked flat but not diving. When it landed gently, it broke the vertical fin. I will rebuild the fuselage and use a fuse DT this time.

Gollywock Crash

Bill Kuhl

Related Links

Thursday, April 26, 2018

Free Flight Hand Launch Glider Story

One of the most important things my model aviation hobby teaches me are those tiny little details can make a big difference to an outcome. Last winter I built a really nice looking free flight glider kit with the intention of adding a hook in front to make it a catapult glider. All the parts were included, very nice manual, carbon boom, and it included jigs to set the angles for the polyhedral wing. As I have had trouble getting the glider to fly properly I am not mentioning the kit name.

From the start, and I started flying it over snow, the glide was fine; the issue was getting a smooth transition from launch to glide. Normally with this type of glider if you are right handed you launch with the glider banked to the right and the glider transitions to a left circle at the top of the launch. This glider refused to do that, often it quickly turned around and dove towards me after launch. I kept trimming off the tiny amount of left rudder but any amount of left rudder would cause the plane to spiral in.

Seeking out the advice of people with more experience I tried their ideas and some of my own. First I put in washout in the tips, good idea but did not seem to help much. I thought maybe the vertical fin was too large so broke off part of that, I think that was needed. If you launch it with a very slight left bank it would transition to left circle now. Flying it over some wet ground helped to cushion the crashes but the front of the nose finally broke off from being wet. I taped a dime to the nose and tried launching again and it improved the launch a little more. Now getting more desperate for a solution I broke off some of the rear of the stabilizer, that helped a little more.

Nice Manual

Back home I rebuilt the nose shorter and added a hook for catapult. Fiberglass cloth was used to cover the nose and the catapult hook. After some hand launching it now seemed that the glider would transition from a straight ahead launch to a left circle. Next I started catapult launching and I was having pretty good results but still it would not take a launch to the right. On one flight the glider was circling nicely in a thermal and headed right over where another model had landed on top of a truck trailer; luckily the glider DT’ed just before reaching the truck trailer. When working with trying to get my airplanes trimmed I lose all track of time, finally around 2 pm I took a break for lunch. Just before that I glued a small amount of rudder back on the vertical fin.

Shorter Nose with Hook

After lunch I flew an electric RC glider and found good lift, at least a couple of times it climbed until it was a speck in the sky. With the glue dry on the free flight glider I tried it again, now it was launching more like it should. On a good launch it hooked a thermal, around and around it circled. It was slowly drifting over an area with blacktop roads. The circling glider started to pick up speed and then the glider was circling in a spiral towards the ground. I was sure hoping the DT would trip, but it hit the hard surface before that. Pieces were flying but the damage was easy to repair.

Working with this glider has been a little frustrating but also very fun. It makes me realize that what appears to be a very simple design might be brilliant in that the proportions of the model are closer to optimum. I feel it has forced me to practice more aerodynamic theory than if I had built a model with a string of contest wins.

Bill Kuhl

Monday, April 16, 2018

Viscous DT on Blue Ridge Special Rubber Model

For a long time I have had this idea about installing a viscous DT (dethermalizer) system on a sport rubber powered free flight model. My first experiment installing a DT system was to install a fuse on a Guillow’s Lancer. This worked well and gave me experience handling a fuse but I wanted to try a viscous system because I wanted a system kids could use without playing with fire. Presently I am writing a couple of articles on viscous DT systems so this would be a good time to try a system on a smaller airplane.

Previously I had built a Blue Ridge Special from plans but lost it this winter on a frozen lake, I had the Volare two plane short kit so decided to build one and install a tiny rotary damper system using the E2 style rotary damper, the price is under $3. To keep the weight of the airplane as light as possible I used really light wood, which the instructions caution against. The leading edge started to bow in but I warped it straight, the problem came back when I covered the plane with Esaki tissue. All the covering was ripped off and laminated a piece of 1/16” square to the leading edge. Recovering went better except now the trailing edge was too soft. When I build the second model I think a light plastic will be used.

To make a timer I referred to Manuel Cisneros article; you remove a plastic gear, slip a tube over the shaft, and place a pin through the shaft. My particular rotary damper appeared to take more force to turn it so I slipped another plastic tube over the first tube to increase the torque. On this same model rotary damper on a glider it turned fine without the extra tube. The rotary damper was mounted on top of the fuselage because I was afraid it might interfere with the rubber motor if mounted on the side. Instead of popping up the rear of the stabilizer I decided to pop up the front of the wing. 

Coming Down from DT 

Recently I purchased a couple of small needle nose pliers with rounded jaws, this tool works good for bending wire in nice looking loops. All the wire used was from a common straight pin. The hinge in the rear of the wing would have a good deal of stress on it so I used a small strip of fiberglass cloth over it. Two sides of 1/16” balsa were used to make a small pylon, a short length of 1/8” square balsa under center of the wing in front slides into the groove between the two pylon sides. This should keep the wing from shifting in flight. A toothpick made a good peg for the DT line to wrap around. 

Everything appears to work fine on the ground, waiting for better weather for test flights. The weight of the plane without rubber was 11 grams, the rotary damper only weigh 3/10 of a gram. When I am happy with how this works I will build the other kit and do a better job of covering the wing.

Bill Kuhl

Related Links    Volare Short-kit 2 Pack  First Blue Ridge rotary damper used  Manuel Cisneros article on rotary dampers Fuse on Lancer video of Lancer flying and fuse DT